Much of the time, like 75% of the time, the character would be 100% clueless about the risks or chances.
The big, huge problem is many players feel they should have a perfect all knowing view of the game, like a DM. And then the player, knowing everything exactly, will decide what actions the character can take. Most of the time, the player wants the conformation of "yes, no matter what it will work", so they can roll and not care and just say "made it".
It's a lot like the false "know it all risk" players get from things like CR.